Smith also commented on the future of Steven Moffat as Doctor Who's showrunner, joking: "He's going to do the next 150 years.

"He is the most wonderful man to work for. He loves Doctor Who. He doesn't want to give up any time soon."

When asked by a fan whether there was a chance of Rose Tyler ever returning to the show, he commented: "They tell us things very late. We tend not to know. But at the moment, we're focused on the fall of the Ponds.

"They are our guys. They're gone. See you later. But I don't know [about Rose]. That would be a Moffat question."

Smith, Darvill and Gillan were all coy on the role of Alex Kingston in the latest series, only admitting that she was "very important" to all the characters.

"We love Alex Kingston. She's the nicest and most flirtatious woman on the planet," joked Smith. "She could flirt with a fish."

The new series of Doctor Who will air in the US and UK in mid-August. Its first screening will be at the London BFI on August 14.